Stock gripper with removable pads



June 3,1947. J, M ,NGALLS 2,421,563

STOCK GRIPPER WITH REMOVABLE PADS Filed Aug. .11, 1944 Patented June 3,1947 UNITED PATENT OFFICE' Jol'nrM. Ingalls, Windsor, Vt., assignor toGone Automatic Machine Company Inc., Windsor,

Via. ai corporation of: Ver

monti Application August 11, 1944,V SerialsNo. 549,043

1&1 Claims.v (Cl. 279-51) This inventionrelatesto -stock gripperssuch'as collets' or jzzush'ers'whi'ch are suitable for grasping lengths ofstockl either while` machining opera'- tions areA 'being'performedY onthose portions of the stock projecting from'the collets', or'ior.'feeding the stock endwise; and' relates'particularlyto such' grippers asare provided' with' removable pads on their inner faces, adapting such a`gripper to takeY stock of4 various sizes and cross' sections asdesired, depending upon the" interior size and conguration' of thevpads:

Pin-object of the present inventionis to provide cooperatingconstructions` of jaws and pads and pad-retaining means suohthatthepadsare' easily removed: and replaced and' whenV in position' are solsecurely' retained that stock may be' rigidly held by the gripper.

A further object is to provide' pad retaining means movable to hold orYrelease the' pads by angular motion about'` the gripper axis.

A still-further object isto so form the retaining means that the-torqueexerted` on' the stock dur'- ing machining operations tends to hold theretaining means in securing position.

Still an'otherobject" of the'inventionA isto provide means readilyaccessible-for moving the retaining means between securing',V andreleasing' positions and for retainingthe securing means in securingposition.

A furtherobjectis to'provi'dea means for securing` the retainer which'when. actuated to secure the retain'erwill also insure. that theretainer is in' tight retaining position.

A further object isto provide constructions by which the pads areinterchangeable between thejawsofe'ach` gripper so that any pads of aset can be' assembled withany j aw of' the gripper for which the set is"designed to cooperate.

This: application is a continuation-impart of my application Serial No.496,604y filed July 29, 1943; for Stock gripper with removable pads.

For' a more complete understanding of this invention, reference may behadV to the accompanying drawings in. which Figure I is a side elevationpartly broken away and in section. on line II of'liigure 2` of a' colletwith pads, constructed. in accordance with this invention.

Figure 2` is a front end elevation` of! the same.

Figure 3 is a perspective view showing the forward' end of the collet,the lpads and retainers being removed; Y

Figures 4 and 5 are perspective views of a pad retaining element and apad, respectively.

Figure 6 is a detail sectional view on line 6E 2' of` Figure 1 and'showing the pads locked' inI position.

Figure 'l is a view similar* to Figure 6', but showing the pads unlockedin condition for removal.,

Figurey 8 is a detaill sectional view on lines-8- of Figure 6.

Figure 9is a view similar l',o1*"igure8;` but` show"- ingY the securingmeans in fully secured position and: with theA retainer in tightretaining position;

Figure 1'0 is a view similar to Figurefl, but showing a modification.

Referring to the drawings, whichshowthe pads applied to a collet of thespring jaw type, at I is indicated the-tubular collet l'iavingv springjaws 2`l formed thereon by the provision or longitudinali slots 3extendingA inwardly from the forwa-rd'endA of thecoll'et toward the rearendthereof; which is continuous circumferentially and is providedwt-hinternal threads as at 4fL by whichl it maybesecuredto anlactuatingv` sleeve in the well known. manner.

The collet jaws have their spring portions provided with the inclinedlor conical surfaces 5 adjacent to their 'freeends for cooperation withmat?- ingl'ytapered surf-aces: (not shown)- on a suitable spindle withinwhich the collet is positioned?, rela-- t-ive axial motionvorthesepartsthen serving to flexinwardly the free end'sof' the springjaws to grip1 the worle or to permitthem' toexpan'd-V and release theworkvwhich extends through the collet.

In order that work of various sizesgand configurations may be grippedbythe collet, the spring jaws arev providedy with removable andreplaceable-Work-engagingpads 6': As shown the interiorsurfaces 1- ofthesepads, together form a cylindricalV surface which is particularlysuitable for engagement with cylindrical Work, but these" inner facesAmight beformedy todefine between thein asquare, hexagonal, or othershaped opening, depending upon the'particular coniiguration of thestock" which the collet may handle at any" particular time and may beofvarious internal" sizes to conform to` the sizeof the stock. The padsand the interior face of the collet are formed .with inter-engagingparts shown as ribs 84 on the pads and' mating longitudinal grooves 9in. the colletV jaws,y which retain the pads and jaws againstdisassembly by relative radial motion, but permitdisassemblyor'assernblyby` relative axial motion'. As shown each of'thev pads,. which covers' slightly71 less than one-third of" a completecircumference of the work, isprovided with two such ribs spaced apart,the remote faces' `Ill' and Il of these' ribs flaring outwardly'radially from each other so that the pads cannot be disassembled fromthe collets by bodily motion of the pads toward the axis of the collet.The ribs and grooves, however, do permit axial sliding motion betweenthe pads and the collet jaws, which thus permits these parts to beassembled or disassembled by relative axial motion. Means are provided,however, by which when the pads are in fully assembled relation to thejaws, they may be held against relative axial motion so that they arelocked against disassembly. As shown such means comprises a retainer I2for each pad, these retainers being mounted to slide angularly about theaxis of the collet in transverse grooves I4 in the collet and throughmating transverse grooves I5 in the pads (see particularly Figures 1, 3and 5).

Each of the retainers. as shown best in Figure 4, is provided with afull slot I6 and a partial slot I'I through which the ribs 8 of the padsmay slide when the retainer is in such angular position that the slotsI6 and I'I are in registry-with the ribs 8. Between the slots I6 and I'Ithe retainer has a retaining portion I8 and at one end a part of asimilar portion I9, and when these parts I8 and I9 extend within theslots I5 of the pads in the position of Figure 6, they obstruct therelative axial motions between the pads and collet jaws and thus preventdisassembly thereof. The retainers are varranged to be held by one ofthe cooperating parts of the collet and as shown are retained by thecollet jaws rather than by the pads.- To this end, each of the colletjaws has an arcuate slot 20 opening out through its forward face andextending through into the transverse slot, I4. A screw 2l rides in eachof these slots 20 and is threaded through a hole 22 in one of theretainers. This screw riding in the slot 20 holds each of the retainersI2 against disassembly from the collet, but when loosened permits asufcient relative angular motion between the retainers of the parts topermit the retainers to be moved between the positions shown in Figure'7 wherein their slots I6 are in registry with the ribs 8 of the padswhich permits these pads to be assembled or disassembled by relativeaxial motion between the pads and the collet, and the positions ofFigure 6V where the locking portions I3 and I9 are partly in alinementwith the two portions 'of the pad ribs on either side of the slot I5,thus preventing disassembly of the pads from the collet.

By manipulation of the screws 2| so that their rear ends bear againstthe rear walls of the collet slots I4, as shownin Figures 1 and 8, theretainers may be pushed forwardly against the opposite walls of theseslots and be thus clamped in adjusted position.

Preferably, and as shown in Figures 4, 8 and 9, the intermediateportions of the retainers are substantially thinner than the widths ofthe grooves Ill and I5 within which they ride and adjacent to oppositeends they are `provided with pads or thickened portions |20 on theirouter faces which slidably lit within the grooves I4 and I5. Thisconstruction permits flexing of the intermediate portions of theretainers by tightening of the screw 2l which passes through itsintermediate portion, as shown in Figure 9, which imparts a yieldinglocking pressure upon the pads and jaws. However, the retainers may beofuniform thickness throughout, as shown in Figure 10, if desired. Ifdesired, also, a tapered 0r= conical seat 2H] may be made in the backface of the groove I4 of each jaw opposite to the screw 2l when theretainer is in its fully retaining position, the sloping side of thisseat 2 I0 acting when the screw 2I is tightened to wedge the retainerinto its limit of retaining position and hold it rmly against motiontoward pad-releasing position. Should it be desired to remove the pads,these screws 2l are loosened so that the retainers are free to be movedin their slots, and they are then moved by pressure exerted on the sidesof the screws 2I to unlocking position. The pads may then be freelyremoved and replaced by pads of a different set which may then be lockedin position by moving the retainers to their obstructing positions andthen clamping them against the slot walls by turning the screws 2| inthe proper direction. The inner end of each screw 2| may, if desired, beslightly headed so as to prevent accidental disassembly of the screwfrom its retainer by too much loosening of the screw, though this willnot prevent suicient motion of the screw to eiect clamping or releasingof the retainers. It does, however, prevent accidental entire removal ofthe screws 2|, which when the `pads are notl in position, would permitthe retainers and screws to become detached with the possibility ofbecoming 10st. It will thus be seen that the retainers may be held withthe collet and that the only parts which are ordinarily removable arethe pads themselves. Thus no elements are likely to become lost, whichif lost, would interfere with the proper functioning of the mechanism.While as shown these pads are applied to a collet, it should, of course,be understood that they might be applied to a pusher or any othertubular stock gripper arranged to permit pads to be assembled ordisassembled with relation thereto.

From the foregoing description of one embodiment of this invention, itshould be evident to those skilled in the art that various changes andmodiications might be made without departing from the spirit or scope ofthis invention.

I claim:

l. A work gripper comprising a tubular holder, work-engaging pads on theinterior of said holder, said pads and holder having interengagingportions permitting relative axial motion between said pads and holderbut preventing radial detachment thereof, and an element rockablycarried by said holder for motion laterally of said interengagingportions between an angular position obstructing said relative axialmotion and an angular position not obstructing such relative axialmotion.

2. A work gripper comprising cooperating parts including a tubularholder and a detachable work-engaging pad on the interior of saidholder, said parts having mating longitudinally extending ribs andgrooves, certain walls of which flare outwardly from the central axis ofsaid holder to prevent disassembly of said parts by relative radialmotion but permitting disassembly of said parts by relative longitudinalmotion, said parts having transverse grooves registering when said partsare in fully assembled relation, and a retainer positioned within andmovable lengthwise of said transverse grooves, said retainer having aslot registering with said lengthwise ribs and grooves in one positionof said retainer in which position said parts may be disassembled, partsof saidretainer bridging said ribs and grooves in another position ofsaid retainer and holding said parts against disassembly.

3. A work gripper comprising cooperating parts including a tubularholder and a detachable workengaging,A pad onr thev interior of said'-holder; said parts havingV mating longitudin-a-lly` extending ribs andgrooves, certain walls of,` which arefoutwardly from the central axis;of saidholder? to prevent disassembly off saidAY parts by relativeradial motion but permitting disassembly of said parts by relativevlongitudinal motion; said,` parts having transverse grooves registering;wheny said parts are in, fully assembled. relation,` a. retainerpositioned Within andmovable lengthwise of said transverse grooves,saidretainerhaving a: slot registering with said lengthwise ribs andgrooves in oneposition of said retainer in which position said parts;may be disassembled,` parts of saidirertainer bridging said ribs and?groovesfin another position-.of said retainer and holding said@ partsagainst disassembly, and meansffor holding said retainer Aassembledrwitlr one of. said partsi 4. A-.worl{ gripper comprisingcooperating:parts including atubular holder anda detaohableworkengaging pad; on`thel interior ofl saidV holder, said parts-having mating longitudinalilyextending ribs and grooves, certain wallsv of1 which: flare outwardly'from the central axis of said? holder to preventdisassemblyof saidvparts byrelativeradial motion. but permitting` disassembly of. saidparts by' relativelongitudinal motion,. said*l parts having transversegrooves registering.l when said parts are. in fullyassem'bledl relation,a retainer'A posi'- tionedA 'vizithin and movable lengthwise. of. saidtransverse grooves, said retainer having aislotv registering with saidlengthwise ribs and grooves in oner position. of: said retainer in whichposition't said parts may be disassembled, parts of saidi retainerbridging said. ribs and grooves in another position of said retainer andholding said parts against disassembly, andY adjustable means forholding said retainer assembledn withone of said parts, said gripperhaving means cooperating with said adjustable meansin one adjustedposition of said adjustable means to secure saidI retainer in oneposition or to release said retainer for such.

movement when said adjustable means is outiof said adjusted position.

5. A Work gripper comprising cooperating parts including a tubularholder and a detachable workengaging pad on the interior of said holder,said parts having mating longitudinally extending ribs and grooves,certain walls of which ilare outwardly from the central axis of saidholder to f prevent disassembly of said parts by relative radial motionbut permitting disassembly of said parts by relative longitudinalmotion, said parts having transverse grooves registering when said partsare in fully assembled relation, a retainer positioned within andmovable lengthwise of said transverse grooves, said retainer having aslot registering with said lengthwise ribs and grooves in one positionof said retainer in which position said parts may be disassembled,portions of said retainer bridging said ribs and grooves in anotherposition of said retainer and holding said parts against disassembly, ascrew projecting from said retainer through an elongated slot in one ofsaid parts and having its opposite end adapted to contact with said onepart, said screw being accessible from one end of said gripper foradjustment to hold said retainer assembled with said one part clampingsaid retainer in adjusted position, or to release said retainer for suchmovement.

6. A work gripper comprising a tubular holder, and Work-engaging pads onthe interior of said holder, said pads having longitudinally extendingribs and said holder having longitudinally extending; grooves into whichsaid ribs, may eX- tend,` mating longitudinal side facesofV said groovesand ribs; flaring outwardly fromthe axis or said-` holder to therebyhold saidA holder and pads against disassemblyby relative radialmotion-.thereo1i but4 permitting disassembly by relative-axial: motionthereof, said ribs andthe stock betweenr sla-idr grooves havingtransverse slots therethrough registering; when said holder and pads.Yarein operativel assembled: relation, pad retainersfslidable4 withinsaid transverse slots and having slots therethrough throughV which; saidribs may pass when said retainer slots are in alinement with said ribsto4 permit disassembly or said' pads from said holder and'movablerout:of alinement with said ribs to retain said' pads' in position, saidrwork` gripper including means for holding said retainers in pad-lockingposition.

7. A worlrV grippercomprising a tubular holder; and: work-engaging padson the interior' of said holden, said@ pads having: longitudinallyextending ribs and' said` holder having' longitudinally eX- permitting,`'disassembly by relative.' axiall motion thereof, said. ribs and thestock. between saidv grooves having: transverse slots therethroughregist-ering;` whensaid holder and pads are in opera:- tiver assembledrela-tiom and: pad' retainers slidable. within'said.- transverse slotsand having slots therethrough through which: said ribs may pass y when?saidretainer slots are inalinement with said ribsto permit' disassemblyof said pads. from' said holder and movableI out of; alinement with said{ribs tofretain saidV pads in position*` 8.. A- workgripper comprising atubular holder, and work-engaging pads on: the interior of said tendinggrooves` into whichf said ribs. may' extend, mating longitudinal sidefaces of said grooves and ribs flaring outwardly from the axis of saidholder to thereby hold said holder and pads against disassembly byrelative radial motion thereof but permitting disassembly by relativeaxial motion thereof, said ribs and the stock between said grooveshaving transverse slots therethrough registering when said holder andpads are in operative assembled relation, pad retainers slidable withinsaid transverse slots and having slots therethrough through which saidribs may pass when said retainer slots are in alinement with said ribs4to permit disassembly of said pads from said holder and movable out ofalinement with said ribs to retain said pads in position, and means forholding said retainers assembled with said holder.

9. A work gripper comprising a tubular holder, and Work-engaging pads onthe interior of said holder, said pads having longitudinally extendingribs and said holder having longitudinally extending grooves into whichsaid ribs may extend, mating longitudinal side faces of said grooves andribs flaring outwardly from the axis of said holder to thereby hold saidholder and pads against disassembly by relative radial Inotion thereofbut permitting disassembly by relative axial motion thereof, said ribsand the stock between said grooves having transverse slots therethroughregistering when said holder and pads are in operative assembledrelation, pad retainers slidable within said transverse slots and havingslots therethrough through which-said ribs may pass when said retainerslots are in alinement with said ribs to permit disassembly of said padsfrom said holder and movable out of alinement with said ribs to retainsaid pads in position, said work gripper including means for holdingsaid retainers in pad-locking position, said retainers having screwsthreaded thereinto and movable in slots in said holder for holding saidretainers assembled with said holder and adjustable to clamp saidretainers in pad-holding adjusted positions or to release saidretainers. v

10. A work gripper comprising cooperating parts including a tubularholder and a detachable work-engaging pad on the interior of saidholder, said parts having mating longitudinally extending ribs andgrooves, certain walls o-f which flare outwardly from the central axisof said holder to prevent disassembly of said parts by relative radialmotion but permitting disassembly of said parts by relative longitudinalmotion, said parts having transverse grooves registering when said partsare in fully assembled relation, a retainer positioned within andmovable lengthwise of said transverse grooves, said retainer having aslot registering with said lengthwise ribs and grooves in one positionof said retainer in which position-said parts may be disassembled,portions of said retainer bridging said ribs and grooves in anotherposition of said retainer and holding said parts against disassembly, ascrew projecting from said retainer through an elongated slot in one oisaid parts and having its opposite end adapted to Contact with said onepart, said screw being accessible from one end of said gripper foradjustment to hold said retainer assembled with said one part clampingsaid retainer in adjusted position, or to release said retainer for suchmovement, said retainer being thinner intermediate to its end portionsthan at said end portions and through which intermediate portion saidscrew extends to be exed on the tightening of said screw to therebyexert clamping pressure of said retainer against said pads and holder.

11. A Work gripper comprising cooperating parts including a tubularholder and a detachable work-engaging pad on the interior of saidholder, said parts having mating longitudinally extending ribs andgrooves, certain Walls of which flare outwardly from the central axis ofsaid holder to prevent disassembly of said parts by relative radialmotion but permitting disassembly of said parts by relative longitudinalmotion, said parts having transverse grooves registering when said partsare in fully assembled relation, a retainer positioned within andmovable lengthwise of said transverse grooves, said retainer having aslot registering with said lengthwise ribs and grooves in one positionof said retainer in which position said parts may be disassembled,portions of said retainer bridging said ribs and grooves in anotherposition of said retainer and holding said parts against disassembly, ascrew projecting from said retainer through an elongated slot in one ofsaid parts and having its opposite end adapted to Contact with said onepart, said screw being accessible from one end of said gripper foradjustment to hold said retainer assembled with said one part clampingsaid retainer in adjusted position, or to release said retainer for suchmovement, said one part having a tapered socket to receive said oppositeend of said screw in position to wedge said retainer laterally of theaxis of said screw toward a limit of pad-retaining position.

JOHN M. INGALLS.

REFERENCES .CITED UNITED STATES PATENTS Name Date Profke Feb. 2l, 1933Number

